COMMUNICATIONS
estrogenic activity. No further work with band 2 is contemplated. ACKNOWLEDGMENT
Cmberger, E . J . , Gass, G. H., Curtis, J. M., Endocrinology 63, 806 (1958). U’inkler, V. W.. Nyman. M. A,. Egan, R. S., Steroids 17, 197 (1971j .
We thank Francis Diaz, Walnut Grove Products, Atlantic, Iowa, for providing adequate amounts of sample for chemical analysis and bioassay tests. We thank Beth Schauerhammer for technical assistance. LITERATURE CITED Association of Official Analytical Chemists, “Methods of Analysis. l l t h e d . . ChaDter 33. 1971. D 639. Christensen, C. M.,‘Nelson, G. ‘H., Mirocha, C. J., Appl. Microbiol. 13,653 (1965). Mirocha, C. J . , Christensen, C. M.. Kelson, G. H., A p p l . Microbiol. 15,497 (1967). Selson, G. H., Barnes, D. M., Christensen, C. M., Mirocha, C . J., Symposium Proceedings 70-0, Extension Service, University of Nebraska, 1970. Stob. M.. Baldwin. R. S.. Tuite. J.. Andrews. F. N.. Gillette. K . G., Nature (London) 196,1318 (1962).
Chester J. Mirocha* Clyde M. Christensen George Davis Glen H. Nelson Department of Plant Pathology University of Minnesota St. Paul, Minnesota 55101 Received for review May 26, 1972. Accepted Kovember 1. 1972. This research was supported in part by USPHS Research Grant No. 5R01-FD-00035-06,Paper No. 7960, Scientific Journal Series, Minnesota Agricultural Experiment Station.
Photochemistry of Mirex
The photolysis of dodecachloropentacyclo[5.3.0.02,6.03,9.04,s]decane(Mirex) in hydrocarbon solvents yielded two major products. These $hotoproducts have been identified as a monohyThe insecticide Mirex (dodecachloropentacyclo[5.3.0.02+6.”3,9.04,s]decane),structure 1, has been used extensively ii, ’le southern United States to control the imported fire an.. This persistent chlorocarbon has been implicated as a possible environmental problem in several recent papers (Lowe et al., 1971; Ludke e t al., 1971; Van Valin et al., 1968).In this report, evidence of Mirex degradation by photolysis in hydrocarbon solvents is presented. In all cases, the elemental analyses, mass spectra, and nmr spectra indicated that chlorine atoms were replaced with hydrogen atoms.
dro derivative and a dihydro derivative. Possible structures for the derivatives (based on nmr, ir, and mass spectra) are discussed.
03~9.04~8]decane). The mass spectra of these compounds (Dilling and Dilling, 1967) indicated that the predominant modes of fragmentation are dechlorination and cleavage of the pentacyclodecane skeleton in half. EXPERIMENTAL SECTION
Technical Mirex, donated by the Allied Chemical Corp., was recrystallized three times from benzene and vacuum dried for 6 hr at 200”. Eastman technical isooctane was distilled twice through a five-ball Snyder column. After being washed with concentrated sulfuric acid, Eastman technical cyclohexane was passed through a sic licic acid column, fractionally frozen, and then distilled. Gas chromatography and ultraviolet spectroscopy were used to establish the purity of all compounds used in the study. Spectral studies were performed with a PerkinElmer Model 270 mass spectrometer, a Perkin-Elmer Model 521 infrared spectrophotometer, and a JEOL Model MH-6011 nuclear magnetic resonance spectrometer. EleI 2 mental analyses were performed by Galbraith Laboratories, Knoxville, Tenn. Mirex in cyclohexane or isooctane (350 ml, 0.04 M ) was placed in an Ace photochemical reactor and irradiated with a Hanovia 450 W, medium pressure, mercury lamp. No differences in the course of the reaction in these two solvents were observed. The Pyrex photochemical reactor and the quartz immersion well were water cooled in order 3 4 to keep the reaction temperature below 32”.The solutions In an investigation of some chemical reactions of Mirex were stirred with a magnetic stirring bar and continuously and related compounds, Dilling et al. (1967) synthesized aerated. The reactions were monitored with a Varian Aerseveral hydrogen derivatives of Mirex. Each product was ograph Model 1400 gas chromatograph equipped with a characterized by elemental analyses, infrared, and nmr flame ionization detector (column: 4 f t x 1 mm i.d.; 0.35% spectra. One monohydro derivative was assigned structure SE-30 on 100/120 mesh textured glass beads; 220”).TWO 2 (1,2,3,4,5,5,6,7,8,9,10 - undecachloropentacyclo[5.3.0. major prqducts were detecfed (retention times relative to 02~6.03~9.04,~]decane), and another monohydro derivative Mirex were 0.70 and 0.55). was assigned either structure 3 (1,2,3,4,5,5,6,7,8,10,10- When 95% of the Mirex had disappeared (48 hr), the undecachIoropentacycl0[5.3.0.0~~~.0~~~.0~~~]decane) ‘or 4 photoproducts (40% yield) were separated from the solu(1,2,3,4,5,5,6,7,9,10,10 - undecachloropentacyc10[5.3.0.02~~.-tion. Preliminary purification procedures involved evapor138
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COI\IMUSICA?'IONS
ating the solvent, vacuum drying the residue on Florisil at 130" and 360 mm pressure, and eluting the photoproducts with hexane. Thje final separation and purification was accomplished with preparative gas chromatography (column: 8 ft x 8 mm i.d. glass; 35% Dow Corning Hi Vac Grease (ethyl acetate soluble fraction) on Kromat FP; 290"). Other coluinns used to verify the purity of the photoproducts were: 4 ft x 1 mm i.d.; 0.35% diethylene glycol succinate (DEGS) on 100/120 mesh textured glass beads (230"); 4 f t x 3 mm i.d. 5% OV-210 on Anakrom ABS (230"); and 50 ft x 0.02 in i.d.; OV-1 support coated open tubular (SCOT) column (180"). Monohydro Derivative of Mirex. The first product produced from the irradiation had a retention time relative to Mirex of '3.70 (SE-30 column). The purified product (decomposed above 350" without melting) gave the following spectra: ir (CC14) 3030 (w), 1230 (s), 1200 ( m ) , 1185 (s), 1152 (w), 1135 (w), 1125 (s), 1110 (s), 1082 (w), 1065 (s). 1030 ( m ) , 1008 (s), 980 (s), 890 ( m ) , 645 (s), 615 (w), 575 (s), 545 ( m ) , and 500 (s) cm-l; nmr (cc14,TMS) 6 3.7 singlet (half-h'eight,2 Hz). Anal. Calcd for CloC1llH: C, 23.50; C1, 76.30; H, 0.197; average mol wt 511. Found: C, 23.68; C1, 76.34; H; 0.22; mol wt (mass spectroscopy) 510 (largest peak in parent ion cluster). Dihydro Derivative of Mirex, The second major product from the irradiation had a retention time relative to Mirex of 0.55 (SE-30 column). The purified product (mp 252-254") gave the following spectra: ir (cc14) 3030 (w), 1230 (s), 1200 ( m ) , 1137 (SI, 1070 ( m ) , 1000 (s), 880 (w), 835 ( m ) , 675 ( m ) , 605 ( m ) , 535 ( m ) , and 490 ( m ) cm-I; nmr (CC14,T M S ) 6 3.7 singlet (half-height, 2 Hz). Anal. Calcd for C1&llOHZ: C, 25.19; C1, 74.37; H, 0.42; average mol wt 477. Found: C, 24.94; C1, 74.24; H , 0.50; mol wt (mass spekroscopy) 476 (largest peak in parent ion cluster). RESULTS AND DISCUSSIOXS
There are only three possible monohydro derivatives of Mirex (structures 2, 3, and 4 ) . The infrared spectrum of the monohydro photolysis product was not identical with either of the two monohydro isomers reported by Dilling et al. (1967). The compound with structure 2 was assigned unambiguously by Dilling; therefore, it can be eliminated as a photoproduct. Dilling et a / . (1967) were unable to choose between 3 and .i for the structure of their monohydro isomer. The gas chromatograms of the purified monohydro photoproduct consisted of one symmetrical peak on four different columns of widely differing polarity [DEGS, OV-1 (SCOT). OV-210, and SE-301. The isomer 2 (Dilling et al., 1!367) is not a component of this material because the retention time of 2 relative to Mirex is 0.75, compared to 0.708 for the photoproduct (SE-30, 210"), and could therefore b.e easily detected. There was no band a t 1600 cm-1 (C=C), and intense bands at 1185 and 1200 cm-1 were present in the infrared spectrum (KBr) of the photoproduct. These bands were not observed (Dilling et al., 1967) in the spectrum of the other isomer ( 3 or 4), and strong bands were reported a t 1257 and 1267 cm-1 in the spectrum of this compound. There were very weak absorptions a t these wavelengths in the spectrum of the photoproduct. Therefore, the photoproduct appears to be the remaining isomer, a t worst contaminated with a small amount of the monohydro derivative 3 or 4 that was prepared by Dilling and coworkers. Photolysis of the purified monohydro photoproduct revealed that it wi2s a precursor of the dihydro photoproduct. The gas chromatogram of the dihydro compound also consisted of a single symmetrical peak on four differ-
ent columns [DEGS, OV-1 (SCOT), OV-210, and SE-301. The mass spectrum of the dihydro product gave major peaks for the C5C15H- ions, but none for the C5C14H2' or C&l,j- ions. The observed magnitudes of the peaks within the isotope clusters agreed well with those calculated from the number of chlorine atoms and the natural abundance of 35C1 and 37C1. Any structure with nonequivalent hydrogens is inconsistent with these data. Furthermore, nmr spectra for both monohydro and dihydro derivatives gave one sharp peak a t 6 3.7, and only 13 peaks were observed in the infrared spectrum of the dihydro photoproduct compared to 19 in the monohydro photoproduct. This suggests that the dihydro derivative has more symmetry than the monohydro derivative. Additionally, three of the adsorptions (3030, 1230, and 1200 cm-1) which are characteristic of C-H stretching and bending modes in similar compounds (de Vries and Winstein. 1960) were identical for the monohydro and dihydro derivatives, Therefore, the possible structures for the monohydro photoproduct are 3 and 4 and for the dihydro compound are ja, jb, 6a, and 6b. Structures j a or 6a were tentatively
5a
5b
6s
6b
chosen for the dihydro photoproduct because the nmr spectra of the mono- and dihydro photoproducts were identical. ACKSOWLEDGMEST
The authors are indebted to the Entomology Research Division of the United States Department of Agriculture for financial support of part of this research. LITERATURE CITED de Vries. L., Winstein. S., J A m e r Chem Soc 82,5363 (1960). Dilling, W. L., Braendlin, H. P., McBee, E. T., Tetrahedron 23, 1211 (1965). Dilling, W. L., Dilling, M. L.. Tetrahedron 23, 1225 (1965). Lowe J. I., Parish, P . R., Wilson, A . J., Jr., Wilson, P . D., Duke, T. W., presented in part at the 36th North American Wildlife and Natural Resources Conference, Portland. Oregon, March. 1971. Ludke, G. L., Finley, M . T., Lusk, C., Bull. Enciron. Contam. Toxicol. G , 89 (1971). Van Valin, C. C., Andrews. A. K., Eller, L. L., Trans. Amer. Fixh Soc. 97,185 (1968)
E a r l G . Alley* Douglas A. Dollar Bobby R. Layton J a m e s P. Minyard, Jr. Mississippi State Chemicd Laboratory Mississippi State Mississippi 39762 Received for review June 12, 1972. Accepted October 5 , 1952.
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